Volume dependence of magnetic properties in Co2Cr1-xYxGa (Y=Ti-Ni) Heusler alloys: a first-principles study

摘要

The magnetic properties tuning and volume dependence in the series ofquaternary full Heusler alloys with formula Co2Cr1-xYGa (Y = Ti, V, Mn, Fe, Co,Ni) were studied with a detailed first-principles exploration. We employ thedensity functional KKR method with the coherent potential approximation,estimating effective Heisenberg exchange constants via the magnetic forcetheorem together with mean-field Curie temperature (TC) and magnetic moment forcompositions in the whole concentration range. The volumetric dependency ofthese magnetic properties is studied, particularly the pressure derivatives ofTC at equilibrium. Our ternary alloy calculations show good agreement withlocal-density and generalized gradient approximations in the literature. Thequaternary alloys show a wide range of tunable magnetic properties, wheremagnetic moments range from 0.8 to 4.9 mu_B, TC from 130 K to 1250 K, anddTC/dV values range from -7 to +6.3 K A-3.